(CNN) -- Gov. Bill Richardson of New Mexico will not pardon legendary Wild West outlaw Billy the Kid in the death of a law enforcement officer more than a century ago, he said Friday.

Richardson made the announcement on ABC's "Good Morning America" the same day he leaves office.

The issue facing Richardson was whether one of his predecessors, Gov. Lew Wallace, promised about 130 years ago to pardon Billy the Kid -- known more formally as William H. Bonney -- for killing Sheriff William Brady of Lincoln County, New Mexico.

Wallace has long been said to have promised a pardon if Bonney testified before a grand jury that was investigating another killing. Wallace did not follow through on that promise, many say, and the reasons are debated.

Richardson said he believes that Wallace did promise to pardon Bonney. Yet there is "historical ambiguity" about why Wallace did not follow through, Richardson said, and he did not want to second-guess the former governor's decision.

"It was a very close call," Richardson said. "The romanticism appealed to me to issue a pardon, but the facts and the evidence did not support it."

The governor acknowledged a positive side effect of his consideration of a pardon.

"It's good for tourism," he said. "It's gotten great publicity for the state."

Billy the Kid was born Henry McCarty but was also known as Bonney and Henry Antrim. He died at the hands of Sheriff Pat Garrett 129 years ago. He was 21 at the time of his death.

Wallace's great-grandson, William Wallace of Westport, Connecticut, has said there is no proof of an offered pardon. "Where is the hard, concrete evidence?" he asked CNN Friday, adding discussion of exactly what happened is full of "gray areas."

While crediting Richardson for "the correct rational track" in his decision, Wallace said "why the governor commenced this nonsense four months ago remains a mystery."

A pardon would have defamed his ancestor, Wallace said. "(Lew Wallace) was a heroic figure in the history of the United States in the 19th century."

Some members of the Garrett family opposed a pardon. Besides arguing that Billy the Kid was an incorrigible killer, they wanted to make sure the sheriff was absolved of any wrongdoing related to the killing.

Jarvis Patrick Garrett, the grandson of the sheriff, cheered the governor's decision Friday.

"Yay! No pardon! Looks like it will be a great New Year!" he said.

Richardson had said he would not do anything that cast a cloud on Garrett.

Some residents, including Governor-elect Susana Martinez, said there are more pressing issues facing the state.

Richardson, a Billy the Kid buff, examined a promise by Wallace, the territorial governor, about 130 years ago to issue the outlaw a pardon.

"A promise is a promise and should be enforced," said Albuquerque defense attorney Randi McGinn, who filed the petition for the pardon and volunteered to handle the case for free.

Following Richardson's decision, McGinn said in an e-mail, "We won the battle (acknowledgement of Lew Wallace's broken promise), but lost the war (the pardon). The historic debate will continue and perhaps a future New Mexico governor will grant justice for the Kid."

Garrett killed Billy the Kid on July 14, 1881, in Fort Sumner, weeks after the outlaw escaped from a jail.

The sheriff, legend has it, was hiding in the dark and shot the Kid when he entered a room. Garrett was gunned down in 1908 at age 57.

Richardson had stressed that he would decide only the matter of Wallace's promise of a pardon.

Wallace -- who had also been a Union general in the Civil War and wrote the novel "Ben-Hur" -- had promised to grant Bonney amnesty for the fatal shooting of Brady and other "misdeeds" if he agreed to testify before a grand jury investigating another murder. Bonney cooperated, but the pardon didn't happen.

According to Mark Lee Gardner and other historians, Bonney at one point wrote to Wallace, asking him to honor the deal.

Garrett's family argues Bonney decided to flee house arrest, making the pardon moot. He eventually was convicted in Brady's death and was sentenced to death, the petition states. But he escaped from jail on April 28, 1881, killing two deputies.

"Still, regardless of Billy's crimes, the motives of Richardson or the hollowness of posthumous justice, it all comes back to Wallace's promise. A deal is a deal, and 129 years doesn't change that. Billy is owed a pardon," Gardner wrote earlier this year in the Los Angeles Times.